I82 



BUDS AND BRANCHES 



333. — Cross section of a leaf 

 bud of the rose, showing the alter- 

 nate arrangement of scales and 

 rudimentary leaves : W, growing 

 point; Zl, youngest leaf ; Z,^, three 

 folded lobes of second leaf; Si^, 

 stipules of second leaf; Sc'^Sc^, 

 scales. 



Compare your drawings with the section of a hyacinth 

 bulb or jonquil, and note the similarity in position of the 



flower clusters. 



256. Study of an Alternate- 

 Leaved Bud. — Examine a large 

 terminal bud of hickory, just 

 about to open. (Apple, pear, 

 cherry, etc., may be substituted 

 if necessary.) How do the 

 scales differ in shape and tex- 

 ture from those already exam- 

 ined ? Pick off the scales one 

 by one, noting their position 

 carefully and illustrating it by 

 a diagram, as shown in Fig- 

 ure 333. This is another variety 

 of the imbricated arrangement, 

 and is by far the most common, 

 though much less simple than that of opposite-leaved buds. 

 How does it correspond with the arrange- 

 ment of leaf scars on the stem ? Refer 

 to Section 52, and say to what order of 

 phyllotaxy it belongs. Notice the grad- 

 ual change in the size and appearance 

 of the scales from the outside toward 

 the center. Can you give any reasons 

 for regarding them as transformed 

 leaves ? Sketch the bud in cross and 

 vertical section (unless this is impracti- 

 cable on account of the fur) and then 

 remove the contents. Notice the copi- 

 ous fur on the inner scales ; of what use 

 is it ? Examine with a lens the little 

 furry bodies within the scales and see 

 if you can tell what they are ; if you can 

 not, get a bud that is partly unfolded and you will probably 

 have no trouble in recognizing them as rudimentary leaves. 



■ Vertical sec- 

 tion of hickory bud ; 

 a, furry inner scales; 

 ^, outer scales; /.folded 

 leaf; r, receptacle. 



